Sodium BiCarbonate is a chemical compound, NaHCO 3 , a
white crystalline or granular powder, commonly known as
bicarbonate of soda or baking soda. It is soluble in
water and very slightly soluble in alcohol. It evolves
carbon dioxide gas when heated above about 50°C, a
property made use of in baking powder, of which it is a
component. It is also decomposed by most acids; the acid
is neutralized and carbon dioxide is given off. The
major use of sodium bicarbonate is in foods, e.g., baked
goods. It is used in effervescent “salts” and is
sometimes used medically to correct excess stomach
acidity. It is also used in several kinds of fire
extinguishers. Although it is an intermediate product in
the Solvay process for making sodium carbonate , it is
more economical to prepare it from purified sodium
carbonate than to purify the intermediate. Because the
bicarbonate is less soluble than the carbonate, carbon
dioxide gas is bubbled into a saturated solution of pure
carbonate, and the bicarbonate precipitates out to be
collected and dried.